Kurdish peshmerga fighters clean their weapons at a base on the closet front line with militants from the al-Qaida-inspired Islamic State in Iraq and the Levant (ISIL), in Tuz Khormato, 100 kilometers (62 miles) south of the oil rich province of Kirkuk, northern Iraq, Wednesday, June 25, 2014. A defiant Prime Minister Nouri al-Maliki rejected calls Wednesday for an interim “national salvation government” intended to undermine the Sunni insurgency by presenting a unified front among Iraq’s three main groups, calling it a “coup against the constitution.” (AP Photo/Hussein Malla)

Kurdish peshmerga fighters clean their weapons at a base on the closet front line with militants from the al-Qaida-inspired Islamic State in Iraq and the Levant (ISIL), in Tuz Khormato, 100 kilometers (62 miles) south of the oil rich province of Kirkuk, northern Iraq, Wednesday, June 25, 2014. A defiant Prime Minister Nouri al-Maliki rejected calls Wednesday for an interim “national salvation government” intended to undermine the Sunni insurgency by presenting a unified front among Iraq’s three main groups, calling it a “coup against the constitution.” (AP Photo/Hussein Malla)

Kurdish peshmerga fighters take their positions behind a wall on the closest front line with militants from the al-Qaida-inspired Islamic State in Iraq and the Levant (ISIL), in Tuz Khormato, 100 kilometers (62 miles) south of the oil rich province of Kirkuk, northern Iraq, Wednesday, June 25, 2014. A defiant Prime Minister Nouri al-Maliki rejected calls Wednesday for an interim “national salvation government” intended to undermine the Sunni insurgency by presenting a unified front among Iraq’s three main groups, calling it a “coup against the constitution.” (AP Photo/Hussein Malla)

Kurdish peshmerga fighters take their positions behind a wall and sand barriers on the front line with militants from the al-Qaida-inspired Islamic State in Iraq and the Levant (ISIL), in Tuz Khormato, 100 kilometers (62 miles) south of the oil rich province of Kirkuk, northern Iraq, Wednesday, June 25, 2014. A defiant Prime Minister Nouri al-Maliki rejected calls Wednesday for an interim “national salvation government” intended to undermine the Sunni insurgency by presenting a unified front among Iraq’s three main groups, calling it a “coup against the constitution.” (AP Photo/Hussein Malla)

People watch an address by Iraq’s Prime Minister Nouri al-Maliki on television at a cafe in Baghdad’s Karrada neighborhood, Wednesday, June 25, 2014. Iraq’s Shiite prime minister on Wednesday called on his nation’s political blocs to close ranks in the face of a growing threat by Sunni militants who have blitzed through the country’s west and north, but he gave no concrete promise of greater political inclusiveness for minority Sunnis. (AP Photo/Karim Kadim)

A fleeing Iraqi girl, cries as she settled with her family in a field near a Kurdish security forces checkpoint, in the Khazer area between the Iraqi city of Mosul and the Kurdish city of Irbil, northern Iraq, Wednesday June 25, 2014. Sunni insurgents who seized Iraq’s second largest city attacked a nearby Christian village on Wednesday, bringing their fight closer to the largely Kurdish regions of northern Iraq which had remained so far largely untouched from the chaos sweeping the country. (AP Photo/Hussein Malla)

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BAGHDAD (AP) â€” Syrian warplanes bombed Sunni militants’ positions inside Iraq, military officials confirmed Wednesday, deepening the concerns that the extremist insurgency that spans the two neighboring countries could morph into an even wider regional conflict. U.S. Secretary of State John Kerry warned against the threat and said other nations should stay out.

Meanwhile, a new insurgent artillery offensive against Christian villages in the north of Iraq sent thousands of Christians fleeing from their homes, seeking sanctuary in Kurdish-controlled territory, Associated Press reporters who witnessed the scene said.

The United States government and a senior Iraqi military official confirmed that Syrian warplanes bombed militants’ positions Tuesday in and near the border crossing in the town of Qaim. Iraq’s other neighbors â€” Jordan, Kuwait, Saudi Arabia and Turkey â€” were all bolstering flights just inside their airspace to monitor the situation, said the Iraqi official, who spoke on condition of anonymity because he was not authorized to speak to the media.

American officials said the target was the Islamic State of Iraq and the Levant, the Sunni extremist group that has seized large swathes of Iraq and seeks to carve out a purist Islamic enclave across both sides of the Syria-Iraq border.

“We’ve made it clear to everyone in the region that we don’t need anything to take place that might exacerbate the sectarian divisions that are already at a heightened level of tension,” Kerry said, speaking in Brussels at a meeting of diplomats from NATO nations. “It’s already important that nothing take place that contributes to the extremism or could act as a flash point with respect to the sectarian divide.”

Meanwhile, two U.S. officials said Iran has been flying surveillance drones in Iraq, controlling them from an airfield in Baghdad. The officials, who spoke on condition of anonymity because they weren’t authorized to discuss the issue publicly, said they believe the drones are surveillance aircraft only, but they could not rule out that they may be armed.

A top Iraqi intelligence official said Iran was secretly supplying the Iraqi security forces with weapons, including rockets, heavy machine guns and multiple rocket launchers. “Iraq is in a grave crisis and the sword is on its neck, so is it even conceivable that we turn down the hand outstretched to us?” said the official, who spoke on condition of anonymity because of the sensitivity of the subject.

The intelligence-gathering and arms supplies come on the heels of a visit to Baghdad this month by one of Iran’s most powerful generals, Qassem Soleimani, commander of the Revolutionary Guard’s Quds Force, to help bolster the defenses of the Iraqi military and the Shiite militias that he has armed and trained.

The involvement of Syria and Iran in Iraq suggests a growing cooperation among the three Shiite-led governments in response to the raging Sunni insurgency. And in an unusual twist, the U.S., Iran and Syria now find themselves with an overlapping interest in stabilizing Iraq’s government.

None-Arab and mostly Shiite, Iran has been playing the role of guarantor of Shiites in Iraq, Syria and Lebanon. It has maintained close ties with successive Shiite-led governments since the 2003 ouster of Saddam Hussein, a Sunni who oppressed the Shiites, and is also the main backer of Syria’s Assad, a follower of Shiism’s Alawite sect.

In a reflection of how intertwined the Syria and Iraq conflicts have become, thousands of Shiite Iraqi militiamen helping President Bashar Assad crush the Sunni-led uprising against him are returning home, putting a strain on the overstretched Syrian military as it struggles to retain territory recaptured in recent months from rebels.

Anthony Cordesman, a prominent foreign policy analyst at the Washington-based Center for Strategic and International Studies, said that with Syria’s apparent willingness to now take on the Islamic State directly, “the real problem is how will Iran, the Iraqi Shiites and the Alawites in Syria coordinate their overall pressure on the Sunni forces?”

Qaim, where the Syrian airstrikes took place Tuesday, is located in vast and mostly Sunni Anbar province. Its provincial government spokesman, Dhari al-Rishawi, said 17 people were killed in an air raid there.

Reports that the Sunni militants have captured advanced weapons, tanks and Humvees from the Iraq military that have made their way into Syria, and that fighters are crossing freely from one side to the other have alarmed the Syrian government, which fears the developments could shift the balance of power in the largely stalemated fight between Assad’s forces and the Sunni rebels fighting to topple him.

Bilal Saab, a senior fellow for Middle East Security at the Atlantic Council’s Brent Scowcroft Center on International Security, said Assad’s immediate priority is to fight the rebels inside his own country.

“His army is already overstretched and every bullet that doesn’t hit enemy targets at home can be a bullet wasted,” he said. “Going after ISIL along border areas could serve tactical goals but is more a luxury than anything else.”

In Brussels, Kerry said Iraqi Prime Minister Nouri al-Maliki appears to be standing by his commitment to start building a new government that fully represents its Shiite, Sunni and Kurdish populations.

However, al-Maliki, in his first public statement since President Barack Obama challenged him last week to create a more inclusive leadership or risk a sectarian civil war, rejected calls for an interim “national salvation government .”

Al-Maliki has faced pressure, including from his onetime Shiite allies, to step down and form an interim government that could provide leadership until a more permanent solution can be found.

Al-Maliki, however, insisted the political process must be allowed to proceed following April elections in which his bloc won the largest share of parliament seats.

“The call to form a national salvation government represents a coup against the constitution and the political process,” he said. He added that “rebels against the constitution” â€” a thinly veiled reference to Sunni rivals â€” posed a more serious danger to Iraq than the militants.

Al-Maliki’s coalition, the State of the Law, won 92 seats in the 328-member parliament in the election, but he needs the support of a simple majority to hold on to the job for another four-year term. The legislature is expected to meet before the end of the month, when it will elect a speaker. It has 30 days to elect a new president, who in turn will select the leader of the majority bloc in parliament to form the next government.

More of Iraq’s sectarian tensions boiled over into violence on Wednesday, with Sunni militants shelling a Christian village 45 miles (75 kilometers) from the frontier of the self-ruled Kurdish region, which has so far escaped the deadly turmoil unscathed.

The shelling of the village of Hamdaniya sparked a flight by thousands of Christians from it and other nearby villages toward the Kurdish region. Hundreds of cars, many with crucifixes swinging from their rear-view mirrors, waited to cross into the relatively safe northern Iraqi Kurdish city of Irbil.

Others were forced to walk, including 28-year-old Rasha, who was nine months pregnant and carried her 3-year-old son on her hip. After her husband’s car broke down, the woman, who would give only her first name for fear of militant reprisals, and her mother-in-law walked for miles toward the checkpoint, fearful she would give birth before reaching safety.

Like most others, the women said they had nowhere to go, but hoped strangers would take them in in the Christian-dominated area.

“Otherwise we will sleep in a park,” Rasha said, shrugging.

Meanwhile, pro-government forces battled Sunni militants, threatening a major military air base in Balad, north of Baghdad, military officials said. The militants had advanced into the nearby town of Yathrib, just five kilometers (three miles) from the former U.S. base, which was known as Camp Anaconda. The officials insisted the base was not in immediate danger of falling into the hands of the militants.